To prevent evaporated fuel which is produced in a fuel tank from being discharged to the atmosphere, in general an evaporated fuel adsorption device which adsorbs evaporated fuel (for example, a charcoal canister) is provided. Such an evaporated fuel adsorption device cannot unlimitedly adsorb evaporated fuel. To prevent the amount of adsorbed fuel from reaching the upper limit value and keep evaporated fuel from no longer being adsorbed, it is necessary to discharge the fuel into the engine intake system.
It has been proposed to provide the evaporated fuel adsorption device with a fuel discharge path constituted by a bypass passage which passes through the inside of the evaporated fuel adsorption device and bypasses a throttle valve (see PLT 1). Due to this, it becomes possible to use the intake which passes through the bypass passage to discharge the fuel from the evaporated fuel adsorption device to the downstream side of the throttle valve.
In this regard, in an internal combustion engine, to lower the combustion temperature to reduce the amount of generation of NOx, if necessary, as inert gas with a large heat capacity, exhaust gas is recirculated to the inside of the cylinder. In an engine intake system in which the above-mentioned bypass passage is provided, the exhaust gas is sometimes recirculated to the upstream side from the inlet of the bypass passage of the engine intake system.